Wired for health

MACHINES that can remotely mend broken minds may herald a new generation of high-tech therapies, say scientists who have discovered how to zap our brains in ways that could relieve stress, treat disease and even make people more dextrous.

Neuroscientists at Arizona State University say they have developed a form of ultrasound that can penetrate the skull and stimulate brain circuits to alter their behaviour. They report in the journal PLoS One that their pulses of low-powered ultrasound can prompt specific neurons in the brain to fire, without damaging any delicate tissues.

William Tyler, the lead researcher, says that the technology has the potential to stimulate brains in ways that block the effects of post-traumatic stress, help to repair brain injury and perhaps even tackle diseases such as Alzheimer's.

He adds that the technology may ultimately also be used to enhance video-game experiences or even create artificial memories in similar manner to Arnold Schwarzenegger's character in Total Recall. “Imagine taking a vacation without even going anywhere,” Tyler says.

Ultrasound is frequently used in medical imaging, but the Arizona team has found that, at lower-than-normal power levels, the soundwaves boost the activity of brain cells, an effect not seen at higher intensities. Ultrasound can also be used remotely, with no need for potentially risky implants for electrodes.

Meanwhile, Harvard Medical School investigators report how they have found that applying electrical stimulation to people's scalps can significantly boost the dexterity of their non-dominant hands. Their tests on 16 right-handed volunteers found that the non-invasive technique, called transcranial direct current stimulation (tDCS), made their left hands nearly 25 per cent more dextrous in a series of skill tests.

The non-invasive technique involves passing a weak current through the scalp to alter the excitability of the underlying brain tissue. The scientists report in BMC Neuroscience that tDCS may prove useful in helping people who have suffered strokes to recover use of their limbs.

Cold Comfort

A CURE for common-cold misery may be a step closer, thanks to Canadian scientists who have discovered that it's not the virus that makes us feel awful but the way our bodies over-react to it.

The human rhinovirus, which causes up to 50 per cent of colds, hijacks our genes and causes an excessive inflammatory response - runny nose and sneezing, say Calgary University findings in the American Journal of Respiratory and Critical Care Medicine.

Tests on 35 volunteers found that within eight hours of being infected, more than 6,500 of their genes had been altered. Many inflammation-prompting genes had been switched up, while genes that produce an antiviral response had been turned down. The scientists hope the finding will lead to new ways to block cold symptoms.

Voice blindness

ARE you a phonagnosic? University College London doctors want to find people who can't recognise voices, after discovering a case of a British woman who can't even discern her daughter's tones on the phone. They report in Neuropsychologia how the woman, known only as KH, has had trouble differentiating voices all her life.

She answers the phone only when she knows beforehand who is ringing. When doctors played her seven celebrity voices, she could identify only that of Sean Connery. The scientists want to know if any other phonagnosics are out there.

Dairy daring

CHILDREN with milk allergies may be cured by consuming tiny quantities of milk under expert supervision, suggest investigators at Duke University, North Carolina.

Their small-scale trial gave 12 children minute amounts of milk powder over four months. By the end of the trial period the children's immune systems were retrained to the extent that they could tolerate up to 5oz of milk without any allergic symptoms.

The study, published in the Journal of Allergy and Clinical Immunology, cautions that while the results look highly promising, parents should not try the therapy without medical supervision.

XXX-ray program

A COMPUTER program that can “mentally undress” even the most baggily clothed person may help professional athletes to compete with less risk of sustaining injuries. Michael Black, a computer science professor at Brown University, Rhode Island, has built a program that makes intelligent guesses at people's body shapes under their clothes, based on 2,400 scans of men and women. It can track an athlete's body as they compete, enabling experts to caution against movements that may cause injury, he told the European Conference on Computer Vision.

Eye-popper

IT WILL make you go blind (or at least shortsighted): sleeping face down, wearing swimming goggles or playing the trumpet may raise the pressure in your eyes enough to damage your sight, says Charles McMonnies, an eye expert at New South Wales University, Australia. He compared various activities for his report in Optometry and Vision Science and concludes that the most harmful thing you can do is to rub your eyes hard (which you'll want to do after reading the study).

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